'use strict';

function get_letter_interval(number_a, number_b) {
  var arr=[];
 if(number_a<number_b){
   for(let i=number_a;i<=number_b;i++){
              var m=String.fromCharCode(i + 96);
              arr.push(m);
   }
  }
   else if(number_a>number_b){
     for(let i=number_a;i>=number_b;i--){
      var m=String.fromCharCode(i + 96);
               arr.push(m);       
     }
   }
   else{
          return [String.fromCharCode(number_a + 96)];
   }
   
   return arr;

 } //在这里写入代码


module.exports = get_letter_interval;
